One interesting feature of the American Platinum Eagle coin is that its reverse design changes every year. The Canadian Platinum Maple Leaf: The Canadian Platinum Maple Leaf bullion coins were issued from 1988 until 2002 by the Royal Canadian Mint (RCM). They were offered in four varieties: 1/10 oz. coin (with a face value (FV) of CD5), 1/4 oz. In fact, it is used as a component in some alcoholic drinks and as a food additive. However, ionic chemical compounds of gold (example, gold chloride) can be extremely harmful to the kidneys and liver. Platinum: Findings by the U.S. federal agency CDC reveal that exposure to platinum salts, on the short term, may cause nose, throat, and eye irritation. This precious metal is characterized as being both polyvalent and versatile. In fact, it is known to be more versatile than any of the other five precious metals in the platinum group. A hard, white metal, ruthenium is known to have four crystal modifications. While it does not tarnish under normal temperature, it does oxidize readily when exposed to air. Ruthenium dissolves only in the presence of oxygen. Rhodium dissolves only when it is in a fine, pulverized form. Iridium and silver do not dissolve under any condition. In another definition, noble metals may refer to electrically conductive elements. Here, the term "noble" serves as a modifying word, such that the electrical conductivity of materials is graded from noble to active. mol-1 (second) The name "osmium" was derived from the Greek word "osme", which means "smell". It was discovered by the English chemists William Hyde Wollaston and Smithson Tennant in London, England in 1803. Wollaston's and Tennant's discovery of the element involved the discovery as well of the other elements in the platinum group. Its two main physical characteristics refer to its hardness as a metal and to its silvery-white color. The former characteristic makes ruthenium ideal for use in making wear-resistance electrical contacts. The price of this precious metal as of January 2010 is estimated to be about USD173 per troy ounce (USD5,562 per kilogram).